本研究应用生物信息学方法，以ORFV NZ2毒株的CBP蛋白氨基酸序列为研究对象，对CBP蛋白的理化特性、亲水性、跨膜区、信号肽、二级结构、三级结构、B细胞表位和T细胞表位进行了预测分析。结果显示，CBP蛋白的相对分子质量为31.179 89 kDa，理论等电点为4.68，半衰期为30 h，稳定系数为43.06，脂肪族指数为81.78，总平均亲水性为-0.383。CBP蛋白为亲水性蛋白，无跨膜区，不属于跨膜蛋白，存在信号肽；二级结构中α螺旋、β折叠、β转角、无规卷曲分别占38.11%、33.91%、5.94%和10.48%，三级结构形似倒立的哑铃，上下对称。筛选出了6个优势B细胞表位、3个CTL细胞表位，无Th细胞表位。CBP蛋白为亲水性膜外蛋白，细胞表位较少，在细胞膜外为ORFV逃避宿主免疫反应发挥作用。本研究为CBP蛋白的功能研究与ORFV的致病机制研究提供了理论依据。
Structural Analysis and Epitope Prediction of CBP of ORFV NZ2 Strain
Taking the amino acid sequence of CBP of orf virus（ORFV）NZ2 strain as the research object，the physicochemical property，hydrophilicity，transmembrane domain，signal peptide，secondary structure，tertiary structure and epitopes of B cell and T cell，were predicted and analyzed by bioinformatics method. The results showed that the relative molecular weight of CBP was 31.179 89 kDa，the theoretical isoelectric point was 4.68，half-life period was 30 hours，stability coefficient was 43.06，aliphatic index was 81.78，and total average hydrophobicity was -0.383. CBP was a hydrophilic protein instead of a transmembrane one，no any transmembrane domain，but signal peptide was contained；α-helix，β-fold，β-turn and random coil accounted for 38.11%，33.91%，5.94% and 10.48% respectively in the secondary structure；the tertiary structure was similar with an inverted dumbbell in form，and it was symmetrical from top to bottom. A total of 6 dominant B cell epitopes and 3 CTL cell epitopes were screened out，and no Th cell epitope was found. CBP was a hydrophilic extracellular protein with few cell epitopes，which helped ORFV avoid host immune response outside the cell membrane. In conclusion，a theoretical basis was provided for the study on CBP' s functions and the pathogenesis of ORFV.